Background: Purine-nucleoside phosphorylase (PNP) is known as a tool for the synthesis of various
nucleosides and nucleoside analogues. Mechanism, properties, molecular diversity and inhibitors of PNP, particularly
these of pharmacological significance, are briefly characterized.
Methods: UV and fluorescence spectroscopy was used for kinetic experiments, and HPLC chromatography for
Results: Applications of various forms of PNP to synthesis of selected fluorescent nucleosides, particularly ribosides
of 1,N6-ethenoadenine and various 8-azapurines (triazolo[4,5-d]pyrimidines) are reviewed. Different
specificity of various PNP forms is described towards nucleobase and analog substrates as well as variable ribosylation
sites observed in some reactions, with a possibility to further modify these features via the site-directed
Conclusion: Present and future applications of the fluorescent or fluorogenic ribosides are discussed, with particular
emphasis on biochemical and clinical analyses with improved sensitivity.